#ifndef __MD5_H__
#define __MD5_H__
 
typedef struct
{
    unsigned int count[2];
    unsigned int state[4];
    unsigned char buffer[64];   
}MD5_CTX;
 
                         
#define F(x,y,z) ((x & y) | (~x & z))
#define G(x,y,z) ((x & z) | (y & ~z))
#define H(x,y,z) (x^y^z)
#define I(x,y,z) (y ^ (x | ~z))
#define ROTATE_LEFT(x,n) ((x << n) | (x >> (32-n)))
#define FF(a,b,c,d,x,s,ac) \
          { \
          a += F(b,c,d) + x + ac; \
          a = ROTATE_LEFT(a,s); \
          a += b; \
          }
#define GG(a,b,c,d,x,s,ac) \
          { \
          a += G(b,c,d) + x + ac; \
          a = ROTATE_LEFT(a,s); \
          a += b; \
          }
#define HH(a,b,c,d,x,s,ac) \
          { \
          a += H(b,c,d) + x + ac; \
          a = ROTATE_LEFT(a,s); \
          a += b; \
          }
#define II(a,b,c,d,x,s,ac) \
          { \
          a += I(b,c,d) + x + ac; \
          a = ROTATE_LEFT(a,s); \
          a += b; \
          }

// 初始化一个 MD5 上下文结构，为后续的 MD5 操作做准备
void MD5Init(MD5_CTX *context);
// 更新 MD5 上下文结构，处理输入的数据
void MD5Update(MD5_CTX *context,unsigned char *input,unsigned int inputlen);
// 结束 MD5 操作，输出 MD5 结果
void MD5Final(MD5_CTX *context,unsigned char digest[16]);
// MD5 操作, 不对外
void MD5Transform(unsigned int state[4],unsigned char block[64]);
// MD5 编码
void MD5Encode(unsigned char *output,unsigned int *input,unsigned int len);
// MD5 解码
void MD5Decode(unsigned int *output,unsigned char *input,unsigned int len);
 
#endif
